Brief Introduction of the XFR series rotameter principle 

 The rotameter constructed in a cross-sectional area of ??bottom-up gradually expanded vertical conical metal tube, equipped with a freely rotating the rotor made of metal or other materials (or float). Is flanked fluid from the bottom of the metal pipe to enter, enters from the bottom from the top of the outflow. 
 When the bottom-up flow of fluid through the vertical tapered tube, the rotor by two forces: First, the vertical upward thrust. Which is equal to the fluid flowing through the rotor and the pressure generated by the conical tube of circular cross-section: the other is vertical down the net weight force. She is equal to the rotor suffered gravity minus the buoyancy of the fluid on the rotor. When the flow to increase the pressure difference is greater than the net weight force of the rotor, the rotor is on the rise. When the net weight force of the pressure and the rotor is equal to the rotor is in a state of equilibrium, to stay in a certain position. Engraved with the outer surface of the metal tube readings. Stay under the rotor position, you can read out the measured fluid flow. 
 The rotameter is a variable cross-section to set the differential pressure flowmeter. Role in the downstream of the pressure difference on the float for a given value. Float and cone Opinion on the annular area change with the flow. The level of float position in the conical tube is reflected in the size of the flow. 
 Set Vf is the volume of the rotor of Af rotor largest part of the cross-sectional area. Pf is the density of the rotor material. P is the measured density of the fluid. If the upstream annular cross-section 1-1 ', downstream annular cross-section 2-2', the fluid flows through the annular surface pressure difference (p1-p2) when the rotor in a fluid in equilibrium, ie rotor withstand pressure = Rotor suffered gravity - buoyancy of the fluid on the rotor. 
 So: 
 (P1-P2) A1 = V1P1g-V1Pg 
 So: 
 P1-P2 = V1g-(P1-P) 
 A1 
 It can be seen from the above equation, when fixed rotameter measuring the flow of a fluid, where Vf, Af, of Pf, p are fixed values. (P1-P2) is also a constant flow. Modeled on the flow of the orifice meter formula can write the formula of the flow of the rotameter. Namely: 
 Vs = CRAR 
 Where: AR - Rotor with metal pipe, circular cross-sectional area, m2; 
 CR - rotameter flow coefficient. Therefore, with the Re value and the rotor shape, experimentally determined or to look up from the instrument manual. 
 When the annulus, see Re> 104, CR desirability of 0.98. 
 From the above equation for a rotor flowmeter measured flow range, flow coefficient CR is constant, the flow only with circular cross section AR change. The metal tube is the next big small cone, the size of the circular cross-sectional area change with the position of the rotor, and thus the level of rotor position can be used to reflect the size of the flow. 
 XFR series rotameter technical parameters 
 ◆ Measuring range: water (20 ° C) :1-200000I / h; air (20 ° C, 0.1.13Mpa); 0.03 ~ 4000m3 / h 
 ◆ Range: Standard: 10:1; special type: 20:1; 
 ◆ Accuracy: Standard: 1.5; special type: 1.0; 
 ◆ pressure rating: 
 Standard: DN 15-of DN50 4.0Mpa; DN80-of DN200 1.6Mpa; 
 Special type: DN15-DN50 the 25Mpa DN80-of DN200 16Mpa 
 ◆ pressure loss at: 7Kpa ~ 70Kpa; 
 ◆ Medium temperature: Standard: -40 ° C ~ 1